In recent years, apparatuses capable of recording information on and reproducing information from an optical disc have been developed. In the case where an optical disc is not stored in a cartridge, there is a high probability that a fingerprint or the like is left on a surface of the disc when a user handles the optical disc. In the case where dirt, such as a fingerprint or the like, is adhered on the surface of the optical disc, there is a probability that the power of a light beam emitted from an optical disc recording apparatus does not appropriately reach a signal recording plane of the optical disc due to the fingerprint adhered on the surface of the disc, and user data to be recorded is not correctly recorded on the optical disc so that user data is corrupted. In order to avoid such a problem, it is necessary to detect dirt, such as a fingerprint or the like, and protect data before recording of user data. In a known conventional technique, during an operation of recording user data, an already-recorded portion of the user data is reproduced, whereby it can be detected if the recorded user data is corrupted due to an effect of dirt, such as a fingerprint or the like, or a defect. Then, a substitution process is performed to change a recording position of the user data.
Operation of a conventional optical disc recording/reproducing apparatus 2100 for recording user data on an optical disc 100 is described with reference to FIG. 21. In FIG. 21, the optical disc 100 is rotated by a spindle motor 101 at a predetermined rotation rate, and user data is recorded on the optical disc 100 according to the power of a light beam emitted from a pickup 103. A traverse motor 102 can move the pickup 103 in a radius direction of the optical disc 100. A user data transmission circuit 108 transmits to a microcomputer 107 user data to be recorded on the optical disc 100. The microcomputer 107 issues to a servo controller 106 an instruction to move the pickup 103 for recording the transmitted user data at a predetermined address of the optical disc 100. The servo controller 106 drives the traverse motor 102 so as to move the pickup 103 such that the light beam is positioned at a designated address.
The microcomputer 107 outputs the user data to a signal recording circuit 105. The signal recording circuit 105 drives a laser incorporated in the pickup 103 based on the input user data to record the user data on the optical disc 100. The pickup 103 detects light reflected from the optical disc 100 with a detector (not shown in FIG. 21) incorporated therein, and outputs a signal generated based on the detected light to a signal reproduction circuit 104. The signal reproduction circuit 104 reproduces the user data recorded in the optical disc 100 and outputs the reproduced user data to the microcomputer 107.
In the case where dirt, such as a fingerprint or the like, is adhered on the optical disc 100, user data cannot be accurately recorded. Thus, the user data cannot be accurately reproduced by the signal reproduction circuit 104. When the microcomputer 107 detects based on a signal output from the signal reproduction circuit 104, that the user data recorded in the optical disc 100 cannot be correctly reproduced, the microcomputer 107 instructs the servo controller 106 to move the pickup 103 such that a position at which the user data is to be recorded is changed to a substitute region on the optical disc 100. The signal reproduction circuit 104 again reproduces the user data recorded in the substitute region and output the reproduced user data to the microcomputer 107. When the microcomputer 107 detects, based on the signal output from the signal reproduction circuit 104, that the data recorded on the optical disc 100 has been accurately reproduced, the above described operation is repeated for performing an operation of newly recording other user data.
By performing the above operation, it is detected that user data is recorded in a portion of an optical disc to which dirt, such as a fingerprint or the like, is adhered, and that the user data is recorded again in a substitute region, whereby the user data can be protected.
According to the conventional technique of using a function of detecting dirt, such as a fingerprint or the like, after user data is recorded on the optical disc, the recorded user data is reproduced for detecting dirt, such as a fingerprint, adhered on the optical disc. The user data is recorded again in a substitute region such that the user data is not corrupted. However, the size of the substitute region has a limit, and accordingly, in the conventional method, the substitute region sometimes cannot contain all of the user data. Further, in the case where dirt, such as a fingerprint or the like, is adhered to the substitute region, user data cannot be accurately reproduced even when the user data is recorded in the substitute region. As a result, there is still a probability that the user data is corrupted.
An objective of the present invention is to provide an optical disc recording/reproducing apparatus having a function of detecting whether or not dirt, such as a fingerprint or the like, is adhered on a disc before user data is recorded, so as to provide caution concerning the dirt, before recording of the user data.
Another objective of the present invention is to provide an optical disc recording/reproducing apparatus having a function of reminding a user to remove dirt adhered on an optical disc.